Nutrition Case Study 3: Hypothyroidism PDF

NUTRITION: HYPOTHYROIDISM Dr. Adam NMT200 Gratton MSc ND October 9, 2023 LECTURE COMPETENCIES Acquire a thorough knowledge of the dietary factors that impact thyroid function. Gain familiarity with the nutritional interventions and strategies utilized in the management of...

NUTRITION: HYPOTHYROIDISM Dr. Adam NMT200 Gratton MSc ND October 9, 2023 LECTURE COMPETENCIES Acquire a thorough knowledge of the dietary factors that impact thyroid function. Gain familiarity with the nutritional interventions and strategies utilized in the management of hypothyroidism. Enhance the skills necessary to provide recommendations and educate patients regarding the dietary modifications essential for hypothyroidism management. Comprehend the significance of essential trace elements in maintaining optimal nutritional health. INTRODUCTION Focus on hypothyroidism with a discussion of some trace minerals Majority of cases of hypothyroidism are a result of Hashimoto’s thyroiditis Goitres from iodine deficiency are rare in North America IODINE Most of the iodine in the body is found in the thyroid and iodine is actively concentrated there Iodine not used by the thyroid is excreted in the urine Major function is to help form thyroxine Iodine released after thyroxine metabolism in the liver is excreted in the bile IODINE RDA is 150 mcg/day or most adults RDA increases to 220 mcg/day during pregnancy and 290 mcg/day during lactation FOOD SOURCES: IODINE Seafood Sea vegetables (kelp, seaweed, etc.) Iodized salt (1 mg of iodine per 10 mg salt) Calcium and potassium iodide food additives in commercially produced bread Toxicity results from intakes of several grams ZINC Component of several body enzymes (zinc metalloenzymes) Vital throughout life but particularly important during periods of growth Involved in protein, DNA, and RNA metabolism ZINC Absorbed in the small intestine Rates of absorption are dependent on body status (low zinc levels = higher percentage of zinc absorbed) Absorption inhibited by alcohol consumption Stored in muscle and bone ZINC RDA is 11 mg for men and 8 mg for women but is ultimately dependent on body size Supplementation can result in copper deficiency Interferes with iron absorption FOOD SOURCES: ZINC Seafood (oysters highest) Meat, eggs, milk Legumes and whole grains Animal sources have higher bioavailability than plant sources COPPER Deficiency is not common Depleted with zinc supplementation RDA is 900 mcg/day Food sources include: seafood (oysters), nuts, seeds Possible leeching with uncoated copper cookware MANGANESE Cofactor for many enzymes (e.g. superoxide dismutase) Involved in amino acid, cholesterol, glucose, and carbohydrate metabolism; reactive oxygen species scavenging; bone formation; reproduction; and immune responses Also plays a role in blood clotting and hemostasis in conjunction with vitamin K MANGANESE Deficiency uncommon but may occur with pancreatic insufficiency Excess accumulates in the liver and CNS leading to psychiatric disturbances and neuromuscular symptoms Toxicity is usually the result of environmental exposure AI is 2.3 mg/day in men and 1.8 mg/day in women Typical diet supplies 1.6 mg/1000 kcal FOOD SOURCES: MANGANESE Grains Legumes Nuts and seeds Leafy vegetables Coffee and tea CHROMIUM Part of a protein complex that potentiates insulin activity and assists with moving glucose into cells AI is 35 mcg/day in men and 25 mcg/day in women AIs go down after age 50 Food sources: brewer’s yeast, liver, cheddar cheese, wheat germ and whole grains SELENIUM Deposited in all body tissues except adipose tissue Concentrations highest in liver, heart, kidney, and spleen Integral to selenoproteins like glutathione peroxidase and deiodinase, among many others Glutathione peroxidase works in conjunction with vitamin E SELENIUM RDA is 55 mcg/day for all adults Supplementation within the context of hypothyroidism is usually around 200 mcg/day FOOD SOURCES: SELENIUM Brazil nuts (68 – 91 mcg per nut) Seafood Legumes Whole grains Lean meats Dairy products FLUORIDE Accumulates in calcified tissues Important during growth of calcified tissues where incorporation of fluoride results in resistance to resorption Fluoride-containing crystals are more resistant to bacterial acids FLUORIDE AI is 4 mg/day for men and 3 mg/day in women Excessive intake leads to pitted and discoloured teeth Toxicity is usually associated with intakes of 10 mg/day or more for 10 years or more FOOD SOURCES: FLUORIDE Fish and fish products Tea Consumption of fluoridated dental products Fluoridated water supplies THERAPEUTICS NUTRITIONAL OPTIONS FOR HYPOTHYROIDISM THERAPEUTIC CONSIDERATIONS Metabolic rates for people with hypothyroidism are slower, especially in untreated patients Energy needs can be 15 – 40% lower Weight gain is common and significant changes in fluid retention can occur Assess caloric intake and adjust as necessary THERAPEUTIC CONSIDERATIONS Ensure iodine and selenium intake are sufficient Incorporate iodine and selenium-rich foods Possible supplementation Avoid excessive iodine intake in those already medicated GOITROGENS Compounds that interfere with thyroid hormone production Usually exert their effect after prolonged use and have a greater effect with iodine intakes are low Many are naturally occurring: thiocyanates, glucosinolates, some flavonoids GOITROGENS Cassava, lima beans, linseed, sorghum, and sweet potato contain cyanogenic glycosides that are metabolized to thiocyanates that compete with iodine for uptake in the thyroid Soy and millet contain flavonoids that impair thyroid peroxidase activity Cruciferous vegetables contain glucosinolates and their metabolites compete with iodine for thyroidal uptake GOITROGENS Food sources are generally considered healthy and should not specifically be avoided Most goitrogens are reduced by cooking the food sources Ensuring iodine intake is sufficient helps offset any effect VITAMIN A Appropriate thyroid function is needed for vitamin A metabolism Lower body level of vitamin A is possible in those with hypothyroidism Consider food sources of carotenoids SAMPLE QUESTION Which of the following trace minerals are directly involved in thyroid metabolism and function? A. Chromium and zinc B. Zinc and iodine C. Iodine and selenium D. Selenium and chromium